Lock.



Patented Dec. 3|, 19m.

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VVITNESSES \K v\\\\ 4 h 4 E... x Z 3 r .2. W 1 V 6/1) r 7:51:25 2 I my w m UNTTE STATES PATENT O FICE.

FREDRIK LEONARD ENQUIST, OF STOCKHOLM, SWEDEN.

LOCK.

SPECIFICATION forming part of Letters Patent N 0. 690,050, dated December 31, 1901.

Application filed December 29, 1897. Serial No. 664,289. (No model.)

To all whom, it may concern:

Be it known that I, FREDRIK LEONARD EN- QUIST, a subject of the King'of Sweden and Norway,and a resident of Stockholm, Sweden, have invented certain new and useful Improvements in Locks, of which the following is a specification.

The main object of my invention is to so construct a lock of this character as to prevent afraudulent duplication of the key from the lock itself.

In the accompanying drawings, Figure -l is a view of the interior of the lock detached from the woodwork and with the bolt-operating devices in section. Fig. 2 is a vertical section at right angles to Fig. 1.

The slidinglocking-bolt 1 is guided,as usual, in the end plate of the casing, and in parts 30 one or more pull-springs 2 being provided to tend to pull the bolt inward, I pivot the tumblers 3 to the sliding bolt 1 by means of a pivot-pin 6, and these tumblers have notches such that when the key turns the tumblers on their pivots against the action of the springs 7 the notches in the tumblers will be brought into line with a fixed fence 1 in the casing of the lock, so that then the springs 2 can draw the bolt inward. The keyhole 1O lies opposite the edges of the tumblers, and the key to be used is a flat key with wards at the end, and is to be inserted into the keyhole simply by pushing it inward longitudinally against the tumblers 3.

The means for throwing the bolt outward against the action of the springs 2 is separate from the key and comprises a push-rod 22, movable in a tube 23 and having at the outer end a knob 21, while at the inner end it acts upon one arm 25 of a bell-crank lever pivoted on a fulcrum 26 in the casing. This lever has another arm 28, which passes through a hole in a bracket 29, fixed to the sliding bolt. The tube 23 is slotted at 27 for the free movement of the arm 25 of the bell-crank lever. The locking-bolt may thus be pushed out by simply pressing the knob 21. In the absence of the spring or springs 2 the bolt may also be withdrawn by the rod 23, if desired. A plate of metal or an escutcheon 31 is preferably inserted in the outer face of the woodwork, this plate having openings for the tube 23 as well as for the key. The guide 3O for the rear end of the sliding bolt does not extend entirely across, but so as to leave a space therein for the tumblers. Flanges 8 on the guides may be employed as stops for the key.

The advantage of the construction described over a lock in which the tumblers are mounted in the casing resides in the fact that when the bolt has been drawn back the parts of the tumblers which were acted' on by the wards of the inserted key have been carried away from the line of the keyhole, and consequently it is practically impossible to get an impression of the positions of the tumblers by inserting a piece of sheet-lead or wood or other relatively soft material through the keyhole for the purpose of fraudulently making therefrom a duplicate key of harder material. In locks of the character described, but with the tumblers pivoted to the casing, the parts of the tumblers which have been acted on by the key remain opposite the keyhole after the bolt has been drawn back, so that it is then an easy matter to make a duplicate key in the manner indicated.

I claim as my invention A look comprising a casing, a spring-acm ated bolt slidably mounted therein, having tumblers pivoted thereto, a fixed fence in the casing, said casing having a keyhole so 10- cated with respect to the edges of the tum blers on which the key must act when the tumblers are in locked position that said key hole will be opposite said edges when the tumblers are in said locked position and at such a distacne from the said edges when the tumblers are in unlocked position as to prevent the insertion of any means for tamper ing with or securing impressions of the said edges in the unlocked position, a removable straightway key adapted to pass through the keyhole and operate on the tumblers in the locked position to unlock the same and permit the spring-actuated bolt to operate, and 5 means separate from the key to throw the bolt in opposition to its spring, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

FREDRIK LEONARD ENQUIST.

Witnesses:

OSKAR RINGSTROM, E. G. WINDAHL.

IOO 

